Identification of signature genes for detecting hedgehog signaling activation in gastric cancer

Hedgehog pathway aberrations and gastric cancer; evaluation of prognostic impact and exploration of therapeutic potentials

Gastric cancer is an important cause for mortality and morbidity worldwide; it lies in the fourt rank as a cause of cancer-related death in males and in the fifth rank of cancer-related death in women. The prognosis of advanced/metastatic gastric cancer cases looks poor with the majority of available therapeutics. Thus, novel therapeutic strategies in this setting have been considered a priority for leading cooperative oncology groups. Hedgehog(Hh) pathway aberrations have sparked particular interest as prognostic markers with data from multiple studies showing consistent evidence of a poor prognostic value of Gli over expression in gastric cancer while on the other hand the prognostic significance of Hh protein over expression (particularly SHH) was not consistent among different studies. This review article revises the prognostic and potential therapeutic opportunities in the targeting of hedgehog pathway in gastric cancer.

Identification of signature genes for detecting hedgehog pathway activation in esophageal cancer

The hedgehog signaling pathway plays an important role in cell growth and differentiation both in normal embryonic development and in tumors. Our previous work shows that hedgehog pathway is frequently activated in esophageal cancers. To further elucidate the role of hedgehog pathway in esophageal cancers we examined the expression of the target genes, hedgehog-interacting protein (HIP) and platelet derived growth factor receptor alpha (PDGFRα) and hedgehog signaling molecules, smoothened (SMO), suppressor of fused (Su(Fu)) in the specimens using in-situ hybridization and RT-PCR. We found that HIP, PDGFRα, SMO and Su(Fu) gene highly expressed in the primary esophageal squamous cell carcinomas but not in normal esophageal tissue. The transcripts of HIP, PDGFRα and SMO were expressed in 13 of 15 esophageal cancers. Su(Fu) expression was missing in 2 esophageal cancers. The results from in-situ hybridization were further confirmed by RT-PCR. Our results revealed a set of genes for detecting hedgehog signaling activation in esophageal cancer.